The commonly used telephone plug (as shown in FIGS. 1 and 2) and Internet link plug at present has to insert into a jack-plug socket to establish connection for communicating with other parties desired or accessing the Internet.
It happens occasionally that users have already inserted the phone plug or Internet link plug into the socket but could not get the connection or communication established. One of the causes of this problem is that a wrong plug has been used. There are generally two types of socket specification being adapted for the phone and Internet link nowadays. One type (socket 7, shown in FIG. 1) has a smaller size of jack 72 for connecting with a smaller size of plug 71. Another type (socket 8, shown in FIG. 2) has a larger size of jack 82 for connecting with a larger size of plug 81. The larger plug 81 cannot be inserted into the smaller jack 72 and won't cause problem. However the smaller plug 71 can be inserted into the larger jack 82 but cannot establish electric connection properly. Users might incidentally do so without awareness as the appearance of the plug 71 and 81 looks almost alike. As a result, the telephone does not work and Internet cannot be logged on. Users might confuse it with telephone disorder or Internet network malfunction. It is an annoying problem yet to be resolved.